Facebook has started rolling out a message to the news feed of the Facebook mobile application that will let users know if their data was improperly shared with data-analytics firm Cambridge Analytica.

When you log into the Facebook mobile app, you should receive one of two messages. One simply directs you towards the Apps & Websites section of Facebook, which allows you to see where you have used your Facebook login details on external websites. Once there, you can remove access to stop your data being shared.

Just waking up in the UK? From around noon you'll see one of these two messages when you go on Facebook. If you get the one on the right, it means you were one of the 1m-or-so British-based users apparently scooped up by Cambridge Analytica pic.twitter.com/HdGMOZn3iX

If you get the second of the two messages however, it means your data was intact shared with Cambridge Analytica. One million or so British Facebook users are reported to be affected.

The message says "We have banned the website 'This is Your Digital Life' which one of your friends used Facebook to log into."

"We did this because the website may have misused some of your Facebook information by sharing it with a company called Cambridge Analytica."

Users that get this message also receive a link to head to the Apps & Websites section of Facebook, to remove access to any external sites.

The Facebook Cambridge Analytica scandal saw the UK-based digital-analytics firm harvest data from more than 50 million Facebook profiles. The company worked on Facebook adverts for Donald Trump's election campaign, but the company insists it didn't use the data during the election.

Facebook CEO Mark Zuckerberg has since issued an apology and laid out a three-step plan detailing how the social media site will restrict access to your data, to prevent something like this from happening again.